Certain bio-affecting agents, or active agents, are most effective when delivered to a host via dosage units which mask their taste and/or which release them over extended periods of time, that is, in about 6 to about 24 hours. Products in which the unpleasant flavor of the drug is undetected are termed "taste-masked." Products which deliver agents over extended time periods are generally termed "sustained release" or "extended release." Among the active agents which are best administered over extended periods are those whose loading doses give adverse reactions and those required to be administered multiple times in a day.
Oral taste-masked and sustained release dosage forms are conventionally prepared by coating drug-containing spheres with materials which alter, respectively, the taste and the rate at which the drug(s) in the spheres become available to the consumer. The application of suitable coatings is complicated when the spheres are too friable, or fragile, to withstand the coating process.
Certain drugs are known to produce very friable spheres. Among them are niacin, acetaminophen (APAP), and aspirin.
The unpalatable nature of APAP and aspirin make them candidates for taste-masked products. Also, when used to treat chronic or long-term pain, they are used several times a day. Patient compliance is improved by masking the taste of these agents.
Niacin, a cholesterol-lowering agent, is a candidate for use in a sustained release dosage unit. When ingested orally, it produces, in significant numbers of consumers, a "flushing," or burning, sensation and gastrointestinal discomfort. These side effects lower patient compliance.
APAP and aspirin are well-known analgesics. When used to treat chronic, or long-term, discomfort, they are administered several times a day. Thus, sustained release forms of these agents are desirable.
Thus, taste-masked/sustained release dosage units of niacin, APAP, aspirin or similar drugs are desirable to achieve therapeutic effects and encourage patient compliance.
Niacin products have been made in the past using technologies such as the following:
U.S. Pat. No. 5,023,245 teaches niacin formulations containing niacin (nicotinic acid), gel-forming dietary fiber and magnesium carbonate. The formulations are taken in capsule form five times a day, with 100 mg of niacin ingested with each dose.
U.S. Pat. No. 5,047,427 shows the treatment of diabetes with a pyruvate salt or with niacin. The agents are administered several times a day. One to three grams of niacin is used daily.
U.S. Pat. No. 5,118,510 describes a drink mix containing coated granules of: niacin, guar gum, a gas-forming agent, and ethyl cellulose. As gas (i.e., carbon dioxide) forms in the stomach, the niacin is released.
U.S. Pat. No. 5,126,145 deals with a controlled release niacin tablet containing a high-viscosity hydroxypropylmethylcellulose (HPMC), a low-viscosity HPMC, hydrogenated vegetable oil or stearic acid, and niacin. From 10% to 35% of the niacin dissolves within two hours of ingestion.
U.S. Pat. Nos. 5,292,534 and 5,427,799 relate to niacin capsules or tablets containing the agent along with xanthan gum and a lubricant. The presence of xanthan gum is taught as diminishing the "flushing" normally associated with niacin use.